Improvement in slide-valves



S. H. DAVISUN.

Slide-Valves.

Patented March 31,1874.

' ATTORNEYS.

ITNES S UNITED STATES PATENT OFFICE. j

SAMUEL n. DAvIsON, OE DAVENPORT, IOWA.

IMPROVEMENT IN SLIDE-VALVES.

Specification forming part of Letters Patent No. 149,203, dated March 31, 1,874; application filed February 21, 1874.

To all whom t may concern .Be it known that I, SAnUEL H. DAvISON, of Davenport, in the county of Scott and State of Iowa, have invented a new and valuable Improvement in Slide-Valves; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings making apart ot' this speciication, and to the letters and figures of reference marked thereon.

Figure 1 ofthe drawingis a representation of a longitudinal vertical section of my slidevalve. Fig. 2 is a transverse sectional view of the same. Fig. 3 is a horizontal sectional view of the same.

This invention has relation to steam slidevalves; and it. consists in certain novel means for relieving the valve from steam-pressure,

y and compensating for the wear ot' the valve On its seat, as will be hereinafter explained.

The following is a description of my improvement:

In the annexed drawings, A designates the valve-chest, and B the valve-seat, through which latter are the two live-steam ports p l) and the exhaust-steam port pf. D designates the back of the valve-chest, which is a vertically-movable casting,having a rectangular hole through it, that communicates with a central chamber in the slide-valve, and also with the exhaust and live steam ports when the valve is Working. This back or top lplate D is held down upon the slide-valve by means of springs t. (Shown clearly in Fig. 3.) The four edges of this top plate D are deeply grooved, and into these grooves packing-strips a are applied, which are forced outwardly by means of springs s. rlhe springs s keep the packing-strips a snugly in contact with the t'our vertical sides ot' the valve-chest A, and prevent live steam from entering the space inside of and on top of plate D, and, the latter being held down by springs t upon the top of the valve, steam will not act O11 this surface. The valve C is rectangular, and has a large opening vertically through it, and it is surrounded by means otl a yoke, C', to which the valve-rod is secured. rlhe yoke C is recessed into the lower external portion of the valve, so that the upper edge of this yoke will not be acted on by steam in the chest.

It will be seen from the above description that I secure all the advantages of a balanced slide-valve, and also greatly reduce the area of the frictional surface to the simple bearing- SAMUEL HIBBARD DAVISON.

Witnesses LOVILO H. BROWN, LEwIs J. BROWN. 

